1. Field of the Invention
The present invention relates to a touch sensitive system, and more particularly, to a touch sensitive processing apparatus and system for despreading and method thereof.
2. Description of the Prior Art
Consumer electronic products have already been necessities of modern life. Such as tablet computers, mobile phones, and other electronic devices, most of them use the touch sensitive screen as their main input/output interface. In addition, they are also configured with WiFi wireless networking devices, such as Bluetooth devices, individual short-distance wireless communication devices, the third or fourth generation of mobile communication network equipment, wireless charging devices, global positioning systems, and so on. These wireless devices require to equip antennas in their thin, short, and limited device bodies. When these antennas transmit signals, they will cause electromagnetic interference with each other.
For example, a projected capacitive touch sensitive screen which is commonly used now, and the touch sensitive control device thereof typically adopts mutual-capacitive detection. It commands a part of or all of electrodes to emit driving signal in order to detect the external conductive objects approaching or approximating the touch sensitive screen. The emitted driving signal and the signal related to the resonance frequency of the driving signal will cause electromagnetic interference with other antennas and wireless devices in the same electronic device. Conversely, other antennas and wireless devices in the same electronic device will cause electromagnetic interference with the driving signal as well when they operate.
Accordingly, when the touch sensitive screen wants to detect the signal of the active stylus, the touch sensitive control device thereof receives not only the signal of the active stylus but also a variety of electronic interference. Therefore, in the case of interference, how to improve the detection rate of the electrical signals emitted by the active stylus in order to further obtain the approximate position of the active stylus on the touch sensitive screen and the sensing values of the sensor(s) on the active stylus are needed technologies required by the market.